The present invention is related to signal processing, and more specifically to smoothing transitions in an ADC.
Generally, signal processing involves the use of a digital signal processor to perform the desired signal processing function. Typically, the following method is used in performing a signal processing function. First, an analog signal is filtered with an anti-alias filter. The analog signal is then converted to a digital signal by means of an ADC (analog to digital converter). Next, a DSP (digital signal processor) is used to perform the desired signal processing function on the digital signal. The digital signal is then converted back to an analog signal by means of a DAC (digital to analog converter). Finally, the signal is filtered with a low pass filter.
The signal processing system described above requires many complex components taking up resources on the circuit. For example, extra power supplies may be needed to provide power to the DSP (digital signal processor), ADC, or other components. Additionally, the available die area on the chip is reduced by each extra component placed on it. For example, the DSP takes up valuable resources on the circuit. Even simple signal processing functions may require many extra components taking up valuable resources.
Many signal processing tracking functions may dither between values, creating a noisy signal. As a result of the noise, unnecessary adjustments within a circuit may be made. What is needed is a way to smooth the transitions and reduce the unwanted noise from the signal processing function.
The present invention is directed at smoothing transitions in an ADC. The invention is also directed at implementing peak detection with minimal complexity and a minimal die area.
According to one aspect of the invention, a reference signal, is used as a starting point and is adjusted by logic to produce the desired peak detection signal processing function that has smooth transitions. Comparisons are made between the reference signal and an input signal. The reference signal is adjusted to obtain the smoothed peak detection function.
According to another aspect of the invention, algorithms implement a signal processing function based on the history of the last n comparisons between the reference signal and the incoming signal, where n is a pre-determined number greater than zero. The algorithm may also generate feedback that modifies the reference signal.
According to another aspect of the invention, a decision level processing circuit that is arranged to make a comparison between the reference signal and an input signal. The decision level processing circuit is configured to produce a desired signal processing function in response to the comparison.
According to another aspect of the invention, a method for performing peak detection for an incoming signal is provided. The method includes making a comparison between a reference code relating to a code and another signal, applying a peak detection signal processing function to the signal, and producing an output signal in response to the comparison and the peak detection signal processing function.